Windows Azure PDT provides a page to configure AppFabric setting for Azure project. You can add or remove AppFabric support in this page.
In the Windows Azure PDT perspective, right click the Worker Role or Web Role project and select the menu Properties-> Windows Azure-> Windows Azure AppFabric , then Windows Azure AppFabric configuration page will be opened.
Here you can add or remove appFabric support on the project you selected. Once you check the button Enable Windows Azure AppFabric support for this role, the AppFabric libraries will be copied to the folder WindowsAzureAppFabricSDKForPHP in the selected project. The folder contains some php files necessary to use Appfabric.